Phase space distributions in information theory

Abstract: We use phase space distributions specifically, the Wigner distribution (WD) and Husimi distribution (HD) to investigate certain information-theoretic measures as descriptors for a given system. We extensively investigate and analyze Shannon, Wehrl and Renyi entropies, its divergences, mutual information and other correlation measures within the context of these phase space distributions. The analysis is illustrated with an anharmonic oscillator and is studied with respect to perturbation parameter ($\lambda$) and states ($n$). The entropies associated with the Wigner distribution are observed to be lower than those of the Husimi distribution, which aligns with the findings regarding the marginals. Moreover, the real components of the entropies associated with the Wigner distribution tend to approach the entropic uncertainty bound more closely compared to those of the corresponding Husimi distribution. Moreover, we quantify the precise amount of information lost when opting for the Husimi distribution over the Wigner distribution for characterizing the specified system. Since it is not always positive definite, the entropies cannot always be defined.